Spain's main political parties cancelled closing campaign rallies today after a former councillor from the governing Socialist Party was shot and killed in the Basque region.
Isaias Carrasco, a father of three, was shot in front of his wife and young daughter in the small town of Mondragon at about 1.30pm (12.30pm Irish time).
"I looked out of the window, and I saw his wife and daughter on top of him shouting 'murderers, murderers'. His chest was covered with blood and they had got blood on them too," a local woman said.
Basque police collect evidence outside the house of a former socialist
There was no immediate claim of responsibility, but Basque separatist groups have often targeted town councillors and carried out shootings.
Socialist Prime Minister Jose Luis Rodriguez Zapatero, who broke off peace talks with the Basque separatist group Eta in December 2006, leads the conservative opposition Popular Party in opinion polls.
Mr Zapatero became prime minister as a result of a surprise election victory following the terrorist attack in 2004, when Islamist extremists killed 191 people by bombing Madrid trains.
The effect of today's killing on Mr Zapatero's chances in Sunday's parliamentary polls was not immediately clear. He has led a crackdown on Eta, but the Popular Party has accused him of being soft on the Basque separatists in the past.
Both the Socialist Party and the Popular Party said they would cancel rallies scheduled for today, the last day campaigning is allowed.
The Popular Party (PP), founded by supporters of former dictator Francisco Franco, was 4 percentage points behind the Socialists on Monday before a pre-electoral ban on publishing opinion polls came into force.
But leftist voters are historically less likely to vote than conservatives, and Mr Zapatero's surprise victory in 2004 was due partly to an unusually high turnout by young voters angered by the then PP government's action in blaming the train bombings on Eta.
Mr Zapatero hopes his socially liberal policies, such as legalising gay marriage and making divorce easier, will bring young voters to the polls despite signs that a decade-long boom fuelled by rising house prices and readily available credit may be ending.